costumegirl

Recently, I have seen quite a few machines with deep crackling/crazing in the finish.

Here is an example:
http://www.ebay.com/itm/Antique-Sing...p2047675.l2557

What are the causes that create this?
Is it large variances in temp from hot to cold? Do damp conditions contribute but not to the point of rusting other parts - the one in the picture has little rust.

If the crazing has a white cast to it like in the pic, might this be a symptom of aluminum corrosion or is it just an opaque clouding of the shellac coat?

Is a symptom of aluminum corrosion white flaking? Is there a way to clean it up and stop further deterioration? Is it wise to just walk away from a machine that may have this?

A thrift store close to me had 2 machines that were similar to the one above - one was really bad, rough to the touch and had whitish patches that appeared to be under the surface. Last year I did pick up a Singer 99 that has crackles in the finish - it isn't even close to the depth of the 2 that I saw yesterday - when the weather gets warmer, I will either give it a go, following Glen's suggestions or just clean her up and live with her imperfections.

SteveH

yes, it is a heat/cooling issue.

BTW - These machines are cast iron, not aluminum

The thread by Glenn on refinishing machines can be used to repair that but it is a bit challenging.

Rodney

The white powder on aluminum is pretty much like rust on iron or steel. Just clean it off and repaint if the finish is too bad to live with. As long as you keep your machine dry it shouldn't get worse. A lot of the time the white aluminum oxide will look worse than what the damage really is once it's been cleaned off.
Steve nailed it on the crazing. Hot/cold cycles. The metal expands and contracts at a different rate than the finish, the elasticity of the finish may play a part as well. A hard brittle finish will crack more/sooner than one that is flexible.
Rodney

costumegirl

Thanks for the info. I really appreciate your expertise since mine is so limited.

One machine that I saw was a 201 (not bad but not the best) and the other was a featherweight 221 (the aluminum one & in poor shape). - they both were high in price and I thought long and hard if they should be coming home with me since I have such limited knowledge on the process of cleaning up. Someday I might try though..... I have to read and research more and then will go for it .....

miriam

I have a couple around here like that, too. I haven't tackled them yet.

Glenn

Yes Steve is right on about the heat and cold. The white glaze to the finish is most likely the shellac that has been in a humid place. The clear coat on the old black singers is shellac and shellac does not like moisture of any kind. If the crazing is in the clear coat it can be repaired but if in the Japanning, that has to be dealt with differently.
Skip